Process for dearomatizing and modifying hydrocarbons with hydrogen fluoride and boron trifluoride



R. E. BURK Aug. 2G, w46.

D MODIFYING HYDRocAfBoNswITH HYDROGEN FLUORIDE AND BORON TRIFLUORIDE PROCESS FOR DEAROMATIZING AN Filed March 6, 1944 Patented ug. 20, i946 UNlTE.

PROCESS FOR DEAROMATIZING AND MODI- FYIN G HYDROCARBON S WITH HYDROGEN FLUORIDE AND BORON TRIFLUORIDE Robert E. Burk, Cleveland Heights, Ohio, assignor to The Standard Oil Company, Cleveland, Ohio, a corporation of Ohio Application March 6, 1944, Serial No. 525,300

Claims.

This invention relates to the dearomatization of hydrocarbon fractions and the subsequent catalytic modification of the dearomatized fraction. More particularly the invention relates to dearomatizaticn using primarily liquid hydrogen fluoride containing a minor proportion of boron trifluoride to remove the aromatics, following which the dearornatized hydrocarbon fraction may be modified catalytically using primarilyrhydrogen fluoride promoted by a minor proportion of boron trifluoride as the catalyst. The invention contemplates the use of the spent catalyst from the catalytic modifying reaction for the removal of aromatics from the hydrocarbon fraction to be catalytically modified.

A preferred and important embodiment of the invention comprises the dearomatization of stocks heavier than gasoline, following Which these stocks are averaged with a light hydrocarbon to form an intermediate hydrocarbon, such as gasoline, from a net consumption of both of said heavier and light fractions.

It is one of the objects of the invention to dearomatize a hydrocarbon fraction, prior to modifying it catalytically, utilizing hydrogen fluoride and a minor proportion of boron triuoride to remove aromatics, and without any subsequent treatment of the hydrocarbon fraction to remove any of the fluorides that may remain in the fraction, prior to the catalytic treatment to modify the same.

A further object of the invention is to dearomatize a hydrocarbon fraction, prior to treating the same with a catalyst, utilizing the spent catalyst from said catalytic treatment for dearomatizing the said fraction.

A further object of the invention is to accomplish the dearomatization and catalytic modification in a countercurrent process in which the hydrocarbon feed is first contacted with the spent catalyst exiting from the process, and last contacted with the catalyst entering the process, whereupon the reaction of the hydrocarbons entering the process is primarily one of dearomatization and the hydrocarbons leaving the process is primarily one of catalytic modification, such as averaging.

Still a further object of the invention is to dearomatize heavier hydrocar-bon fractions and then average the dearomatized fraction with a light hydrocarbon, such as butane, utilizing a material of similar or identical composition to accomplish both processes.

Still a further object of the invention is to carry out all of the actions indicated above with the hydrocarbons in a liquid phase in the presence of a catalyst in a liquid phase.

Another object of the invention is the provision of a process in which fluorides containing the impurities present in commercial grades may be used as the catalyst.

Still a further object of the invention is the provision of a process which may be carried out under conditions of temperature and pressure not materially lower nor higher than can be obtained conveniently in ordinary plant and refinery operations such as currently practiced. The invention has as a further object the provision of a process in which the activity of the catalyst, both in the dearomatizing action and in the catalytic modifying reaction, may be controlled by variations in temperature, pressure and other factors ordinarily available, and also can be controlled readily by means of variations in the amount of the boron trifluoride constituent of the catalyst.

The invention will be understood from the following description taken in connection with the drawing which illustrates a preferred form of the invention in a diagrammatical flow-sheet.

Hydrogen fluoride boils at about 67 F. and is therefore a liquid at temperatures just under room temperature and may be kept liquid at higher temperatures by moderate pressures. The temperatures and pressures used are conveniently those that maintain the hydrogen fluoride liquid. Boron trifluoride boils at F. and is a gas at the temperatures and pressures conveniently employed in hydrocarbon treating processes, However, boron trifluoride dissolves in liquid hydrogen fluoride to a given extent and the amount that dissolves at any given temperature depends on the partial pressure of boron trifluoride. At higher partial pressures, a larger amount of boron trilluoride is dissolved.

The boron trilluoride in the hydrogen fluoride in the liquid phase possibly may react at least to some extent, but an understanding of the chemistry involved is not necessary to practice the invention, and I do not intend to be bound by any theory. At any event, the amount of the boron trifluoride in the hydrogen fluoride is a function of the partial pressure of the boron triiluoride at any given temperature. The amount of boron trifluoride dissolved in the hydrogen fluoride, at any given temperature, may be expressed conveniently in terms of the partial pressure of boron trifluoride. The Words dissolved and solution are used as generic to both a physical admixture and a reaction product,

'during the averaging process.

tend to accumulate in the catalyst phase.

It has been discovered that a wide variety of hydrocarbons may be modied catalytically as to their hydrocarbon content, that is their molecula1` weight may be altered or their chemical configuration changed, or both, or they may be reacted with other hydrocarbons by subjecting the hydrocarbons to a liquid catalyst comprising liquid hydrogen fluoride which is contained a minor proportion of boron trifluoride under a positive partial pressure of Y boron trifluoride.

Such processes, for example, include averaging" in which a heavier hydrocarbon fraction, such as kerosene or higher naphtha, may be reacted with a. light hydrocarbon, such as a butane, to produce hydrocarbons intermediate said light and heavier hydrocarbon fractions, such as gasoline, and which results from a net consumption of both fractions. Other reactions that may be accomplished include, for example, isomerization, cracking, alkylations, etc. The process of averaging is typical of a catalytic reaction in which the liquid fluoride catalyst may be used, andwill be further referred to as illustrative in connection with a more detailed explanation of. the invention.

In carrying out the averagingreactiona higher boiling fraction, such as kerosene, and the lower boiling fraction, such as a butane fraction, are contacted with each other in the presence of the liquid catalyst under conditions of temperature and pressure for a length of time and under other conditions as will be pointed out more particularly hereinafter. At the conclusion of the treatment, the hydrocarbons and the liquid catalyst may be settled in two phases. 4The hydrocarbons comprise the upper or lighter layer. The liquid catalyst comprises the heavier layer; because it separates as the lower of the two layers, it is often referred to hereinafter as the lower layer.

In the catalytic hydrocarbon modifying processes, such as averaging, where one or more or all of the hydrocarbon fractions entering into the reaction contains aromatics, the catalyst is deactivated by any substantial amount of aromatics present. This is particularly troublesome since kerosene and Vnaphtluas, whichare often used in averaging, may contain a suiiiciently large proportion of aromatics to deactivate the catalyst Extended studies have shown that the aromatics present in an Illinois kerosene to the extent of 17% greatly retard tion in addition to that which is deactivated by the aromatics, this procedure is not as desirable in many instances as a preliminary dearomatization of the stock containing the aromatics. The aromatics for the most part leave the hydrocarbon phase and go into the lower layer.

During the averaging reaction, hydrocarbons These are thought to comprise primarily unsaturates which may be present in either the heavier or light fraction feeds, or unsaturates which may be formed during the averaging process, and which go into the catalyst `phase rather than react in the averaging reactions. I f the stock is not sufiiciently dearomatized, aromatics may also accumulate in the catalyst phase. The presence of any aromatics, and the presence of unsaturates beyond the point where they function as an activator, in the catalyst phase has a poisonous, ef-

fect upon the catalyst and eventually theV acy cumulation of these hydrocarbons in the catalyst decreases its activity to such an extent that it is no longer economically feasible to continue using the catalyst. This is particularly so if the stock contains a significantly large amount of aromatics. If desired, the spent catalyst may be regenerated by any of the processes described hereinafter, that is the fluorides may be separated from hydrocarbons and the fiuorides reused.

In accordance with the invention, it is possible to use substantially the same material that is used as a catalyst in the averaging reaction to act as an extracting material for the removal of aromatics from the heavier hydrocarbon fraction being used in the averaging reaction. In accordance with this operation the heavier fraction is subjected to a liquid material comprising liquid hydrogen fluoride containing dissolved boron trifluoride, under pressure, temperature and other lconditions to be pointed out more particularly hereinafter. Following this the mixture is settled and the dearomatized heavier fraction will comprise the upper laye1` and the lower layer will comprise the iluorides in the liquid phase in which the aromatics are contained. These two layers can be settled, and the dearomatized heavier fraction may then be transferred to the averaging reaction zone.

Y A small amount of the fluorides may be soluble in the upper hydrocarbon layer. It is significant to note that it is not necessary to remove these prior to the treatment of the heavier fraction in the averaging reaction, since the same material is there used as the catalyst. This is to be distinguished from processes where another material may be used as a catalyst, which would be adversely affected by the presence of the uorides; it is also to be distinguished from processes in which another material may be used for extracting aromatics which would adversely affect the later catalytic reaction or the uorides if not completely removed from the raffinate.v

In accordance with the preferred embodiment of the process, it has been discovered that although the spent catalyst from the averaging reaction may be deactivated during averaging insofar as the averaging reaction is concerned, it-is still active for extracting aromatics from the heavier hydrocarbon fraction. In accordance with this embodiment, therefore, it is possible to Yuse the fresh catalyst for the averaging of dearomatized kerosene and butano, for example, until the catalyst becomes deactivated for the averaging reaction to an extent which justifies its replacement. This spent catalyst may then be used for the treatment of the heavier hydrocarbon fraction feed stock containing aromatics, in order to dearomatize the same, and the feed stock thus dearomatized may then be fed to the averaging reaction zone. It will be readily apparent that such a. process may be carried out conveniently in a countercurrent operation, either of a truly continuous type, or in a semi-continuous process, involving a plurality of stages.

The catalyst phase left from the dearomatization, irrespective of whether it was fresh uorides or the spent catalyst from the averaging reaction, in which the aromatics have accumulated during the dearomatization, may be regenerated by separating the iiuorides from the hydrocarbons in accordance with any of the regenerating methods described hereinafter. The regenerated uorides may be recycled either to the 4averagingV or dearomatization. The hydrocarbons separated duringV the regeneration may be processed such as by cracking, hydrogenation, etc., or used as fuel.

The action of the iiuorides in removing the aromatics, strictly speaking, is not one of catalysis. The process is more in the nature of an extraction.. For convenience, however, the liquid hydrogen fluoride containing boron trifluoride is referred to herein as a catalyst even when used for dearomatization.

The following examples are given merely as illustrative of the manner in which a heavier fraction maybe dearomatized prior to averaging with butane. 'Ihe percentage of arcmatics is that determined by the Kattwinkel test.

Example 1 A kerosene containing 18% aromatics was treated with volume per cent of hydrogen fluoride and an amount of boron trifluoride to provide a partial pressure of 150 pounds per square inch. The treatment was continued at 90 F. for a period of minutes. The hydrocarbon phase was separated from the fluoride phase. The amount of aromatics in the raiinate was reduced to 6%.

Example 2 The same kerosene stock was treated with volume per cent of hydrogen fluoride and an amount of boron trifiuoride to provide a partial pressure of 50 pounds per square inch. The action was continued for 15 minutes at 90 F. The raflinate contained 7% aromatics.

Example 3 The same stock is treated with volume per cent hydrogen fluoride and boron trifluoride in an amount to provide a partial pressure of 150 pounds per square inch. The treatment was continued for 15 minutes at 90 F. and the rafnate was found to contain 3% aromatics.

The above examples illustrate an embodiment of the invention using fresh uorides in the dearornatization. From these examples it will be seen that thearnount of hydrogen iiuoride and the partial pressure of the boron trifluoride may be adjusted to reduce the aromatic content of the hydrocarbons to the various levels as found desirable in the catalytic operation using the dearomatized kerosene. Depending upon the economics involved, a point will be reached where the increased amount of catalyst required to reduce further the aromatics is not reflected in an improvement in the catalytic reaction.

Example 4 A butane fraction containing 15.7% isobutane was averaged with a Pennsylvania kerosene dearomatized by any of the above processes and containing about 2% aromatics. The Volume of the butane' fraction based on the kerosene was 200% and the weight of the kerosene based on the total hydrocarbon charge was 40.6%. The amount of the hydrogen uoride based on the total hydrocarbon charge was 33.7 volume per cent, and the amount of the boron triiiuoride was such as to provide a partial pressure of 150 pounds per square inch. The total pressure was 200 pounds per square inch. The hydrocarbons and the catalyst were agitated under these conditions at a temperature of 90 F. for one hour. The hydrocarbon phase, upon its separation from the catalyst was found to contain, by weight,

alioaoos 0.8% of hydrocarbons lighter than C4, 53.2% butanes of which 54.4% was isobutane. The hydrocarbons boiling within the range of to300 F. amounted to 21.6%. The hydrocarbons boiling within the range of 300 to 400 F. amounted t0 3.4%, and those boiling above 400 F. amounted to 10.2%. 8.6% of hydrocarbons was found in the catalyst phase. Experimental loss in the handling of the material, amounting to 2.2%, is unaccounted for. Calculations showed that about 11% of the butane feed entered into the reaction. The recovered butane fraction and the fraction boiling above 300 F. may be recycled to the averaging zone, resulting in a net consumption of 39.2% of the charge. Of this, 55% is converted into hydrocarbons in the gasoline range.

Eample 5 A kerosene containing 16-18% aromatics was treated with 16 volume per cent of liquid hydrogen fluoride based upon the kerosene and an amount of boron trifluoride to provide a partial pressure of 150 pounds per square inch. The treatment was continued for 15 minutes with agitation at a temperature of F. The raffinate was found to contain 6% aromatics. The rafnate from the above dearomatization, without any removal of fluorides dissolved or otherwise contained therein, was then mixed with a butane fraction in the proportions of 57% by weight of the butane fraction and 43% of the raiinate. The amount of isobutane in the butane fraction was 52.6%. All of the ra'inate boiled above 300 F. The mixture was subjected to a catalytic treatment with volume per cent of hydrogen fluoride (based on the hydrocarbons) and an amount of boron trifluoride to provide a partial pressure of 150 pounds per square inch. The total pressure was 250 pounds per square inch. The reaction was continued for 15 minutes at a temperature of F. The hydrocarbons were separated from the catalyst phase and upon fractionation were found to contain 0.4% of C3 or lower hydrocarbons,55.3% butanes, of which about 60% was isobutane, 15.4% boiling in the gasoline range (from isopentane to 300 F.) and 20.8% boiling above 300 F. The catalyst phase comprised 8.1%. Based upon the rafinate charged, the yield of gasoline was 36%. If desired, the unreacted butanes and the products boiling above 300 F. may be recycled. Based upon the hydrocarbons not recyclable, the yield of gasoline was 64%.

Example 6 The same kerosene was dearomatized in accord- -ance with the same process as that described in 'Example 5 and averaged With butane under the drocarbons, 57.4% were butanes, 58% of which was isobutane. The fraction boiling in the gasoline range was 16.6% and the hydrocarbons boiling above 300 F. amounted to 17.1%. The catalyst phase contained 7.9%.

The yield of gasoline, based on the rainate used was 40%, and the yield of gasoline, based on the hydrocarbons, not recyclable to the averaging reaction zone in a continuous process, amounted to 65%. K'

7 Example 7 As illustrative of a continuous process in which the spent catalyst from the averaging reaction is used to dearomatize the heavier hydrocarbon feed stock for an averaging process, a fraction of crude, boiling between 50 and 550 F. and containing 10% aromatics. was utilized as the heavier fraction. To start the process, the crude was extracted with 10 volume per cent liquid hydrogen fluoride and an amount of boron trifluoride lto provide a partial pressure of 150 .pounds per square inch. Dearomatization was continued for 15 minutes at 90 F. and the amount of aromatics in the raiiinate was reduced to The raflinate was then averaged with butane,

the amount of butane charged being 58.4% and Y the amount of raninate charged being 41.6%. The butane fraction comprised 29% isobutane. The reaction Was continued for V30 minutes at a temperature of 90 F. The catalyst used comprised 100 volumes per cent hydrogen fluoride (based on the hydrocarbons) and an amount of boron triiluoride to provide a partial pressure of 150 pounds per square inch. The total .pressure was 250 pounds per square inch. The mixture was settled and the hydrocarbon phase was found to contain 57% butane, and 0.7% of C3 or lower hydrocarbons. 'I'he fraction boiling in the gasoline range (isopentane to 300 F.) amounted to 25.1%. Of .this fraction 13.5% was isopentane, although none was contained in the dearomatized crude. The fraction boiling above 300 F. was 14.2%. The catalyst phase contained 3.0%.

The spent catalyst from the above averaging reaction was utilized to dearomatize an additional quantity of the same crude stock, boiling between 50 and 550 F. and containing 10% aromatics. The crude was treated with the spent catalyst at a temperature of 90 F. for a .period of 15 minutes in the presence of suiiicient boron trii'luoride to provide a partial pressure of 150 pounds per square inch. The aromatics were reduced from 10 to 3%. The fraction dearomatized with the spent catalyst was then averaged with butane under conditions indicated heretofore in the example.

In the dearomatizing process, any fraction may be treated which contains aromatics, i. e., a fraction with constituents boiling above about 175 F. For the most part, such fractions are formed from parains but they may contain naphthenes, unsaturates, etc., as Well as aromatics. The exact chemistry involved in the removal of the aromatics is not entirely understood, but it is thought that the aromatics form a loose chemical complex with the uorides at the temperatures used which is miscible in the liquid fluoride layer. The complex can be dissociated at high ytemperatures and the iluorides liberated.

The .conditions under which the dearomatization can be accomplished are pointed out hereinafter, and also in Patents Nos. 2,343,744 and 2,343,841 to be granted on March 7, 1944, any necessary part of the disclosures in which are incorporated herein by reference.

The averaging reaction may be carried out with a heavier fraction predominately Ce Yand higher hydrocarbons, preferably boiling above the gasoline range. The light fraction may be preferably butane or butanes, although .propane and pentane can be used in some cases. The butane vfraction may comprise normal butane and the normal butanemay be the net product consumed in the averaging. l

`the reaction time and temperature.

V The proportions of the heavier and light fractions should be one mol of the heavier fraction to at least one Kmol of the light fraction. When using butanes, 2 to 4 mols of butane per mol of the heavier fraction is preferred. No appreciable economic advantage accrues from the use of more than V6 mols of butano, although as high as 10 mols or more may be used if desired for other reasons. i

The unreacted light fraction may be recycled to the averaging reaction zone and the net feed of'the light fraction need be only that consumed in the reaction. This may be a normal hydrocarbon. The light hydrocarbon which does not enter into the averaging reaction may be isomerized to a large extent and the recycle stock may be predominately vthe isomer. This is advantageous under some conditions. A portion or all of the isomer may be withdrawn and the balance recycled. The withdrawn portion may be replaced by fresh feed which may be a normal hydrocarbon. Thus, normal butane may be isomerized simultaneously with the averaging.

An olen may be included in a small amount in either fraction and Jthe presence of the same in an amount of 1 to 10%, and not over 25%, based on the total hydrocarbons acts as a promoter. Too large an amount acts to poison the catalyst.

The conditions under which the dearomatization and the averaging or other catalytic operations are carried out, may overlap to a large extent and under some conditions may cover about the same range. In general, the averaging temperature may vary from -30 to 400 F. and the dearomatizing temperature from -30 to 300 F. Preferably the same or different temperatures within the range of 32 to 212 F. may be used in rthe dearomatizing and averaging. It is an advantage that extreme temperatures in either direction are not necessary. The temperature should be adjusted with reference to the amount of catalyst, and the partial pressure of boron tri# fiuoride and other conditions. A single temperature may be used in the averaging and in the dearomatizing, or it may be varied during either or both of these actions. The temperature also may be dependent upon the activity of the catalyst. For example, a fresher catalyst in the averaging or one having a higher boron trifluoride content may be used with' a lower temperature. In the dearomatizing the temperature may be adjusted with reference to the extent to which the catalyst is spent and the amount of aromatics to be removed.

The amount of fluorides employed must be considered with reference to both of the fluoride ingredients. The amount of hydrogen iiuoride may be from 5 to 300 volume per cent, based on the hydrocarbons to be treated and the other conditions, preferably an amount of 10 to 100 volume per cent. The amount may also be gauged with reference to the nature of the materials being treated. In the averaging reaction the amount may depend upon the reactivity of the stocks and their nature. In the dearomatizing reaction the amount used may be lower but this depends on the amount of aromatics to be removed and the degree to which' a catalyst has been used. The amount of boron triuoride used, as expressed in terms of partial pressure, may be from a, :few

pounds toA 550 pounds per square inch, preferably 50 to 250 pounds per square inch. This must be related to the amount of hydrogen fluoride used, Under no circumstances should the amount exceed 50 mol per cent of the fluoride. In the dearomatization fthe use of a higher partial pressure of boron trifluoride permits the use of a smaller amount of hydrogen iiuoride and vice versa.

One of the advantages of the process of the invention is the ability to control the activity of the catalyst through control of its composition. This may be accomplished by varying the partial pressure of the boron triuoride, because a change in this partial pressure results in a change in the amount of boron trifluoride dissolved. If the partial pressure of the boron triluoride is increased, by admitting boron trifluoride from a high pressure source of supply, the activity of the catalyst is greater and it has a greater ability to dearomatize under conditions otherwise the same. If this partial pressure is decreased, by bleeding boron triuoride, the activity is reduced.

The hydrogen fluoride and boron trifluoride may be the available commercial grades. It is not necessary to have chemically pure fluorides. The impurities in the commercial grades, including water, which are generally present in an amount of about 1/4 to 5 per cent, do not interfere materially with the operation of the catalyst. In view of the economic advantage of using the commercial grade, it is preferred, and was used in the foregoing examples. Reference to the fluorides hereinafter is intended to include such commercial grades and their normal impurities or their equivalent in composition.

The total pressure in each instance should be sufficient to keep the hydrogen fluoride in the liquid phase in both the averaging and the dearomatizing and preferably also to keep all of the hydrocarbons in the liquid phase. The pressure, of course, must exceed the partial pressure of boron triluoride used and may be in excess of the sum of the partial pressures of the boron triiluoride, hydrogen fluoride, hydrocarbons, if other materials, for example, hydrogen, are present. It is an advantage of the process, however, that high pressures are not required.

The time of contact between the hydrocarbon and the iiuorides will vary with the temperature, thoroughness of contact or mixing, the composition of the fluoride mixture, and other factors. The dearomatization can generally be accomplished in a much shorter time as the formation of a complex with the aromatics appears to proceed quite rapidly. If the dearomatization is carried out under conditions which are not conductive to other reactions, it is not material if the time is extended somewhat beyond the period necessary to dearomatize. If some other reaction is to take place in the dearomatizing step, the time should be selected with this in mind. The time in the averaging reaction should be selected to give the optimum yield of the desired products and this may vary from 5 minutes to 3 hours, depending upon the reactivity of the hydrocarbons, temperature used, composition of the catalyst, and in particular, upon the thoroughness of mixing. With the thoroughness of contact available with the best commercial mixing apparatus, and at the optimum temperatures, the time might be reduced to an order of a few minutes. At Very low temperatures a longer time is required.

The agitation may be accomplished with any type of a mechanical agitator or stirrer, or it may be accomplished by inducing flow such as would result from the introduction of one of the ingredients into the reaction zone through an orifice under high pressure.

The temperature, composition of the catalyst, time of Contact, and other factors mentioned heretofore, are more or less interdependent. The ranges described heretofore are not intended to mean that any temperature may be used with any length of time or any composition of catalyst to obtain the identical result. For example, if a lower temperature is used, a somewhat larger amount of catalyst may be present or a somewhat higher partial pressure of boron triiluoride may be used, or the treating time may be longer, or any or all of them, to obtain about the same result that would be obtained with a higher temperature and with a lesser amount of catalyst, or a lower partial pressure of boron trifluoride, or with a shorter treating time. Thus, for example, any temperature within the range may be employed and the other variables may be adjusted within their ranges so as to obtain averaging. The temperature may affect the rate of the reaction as well as the equilibrium point and should be selected with this in view.

It is a particularly important part of the process that in addition to varying the time of con-Y tact, the amount of catalyst, and the temperature, which are the variables with which the prior art has had to work, it is possible, in accordance with the process to vary the composition of the catalyst by varying the partial pressure of the boron fluoride. If the effective ingredient for catalyzing averaging or removing aromatics is viewed as the combination of the'two fluorides, the amount of said ingredient will be dependent on the partial pressure of the boron trifluoride. Thus, for any given temperature, time of contact, etc., at which it is desirable to operate be cause of plant equipment or economic reasons, the rate of the reaction and the activity forvthe catalyst can be varied simply by adjusting the partial pressure of the boron trifluoride.

The relation of the conditions is also dependent upon the nature of the hydrocarbons being treated. It might seem somewhat paradoxical that substantially the same conditions could be used for averaging as could be used for dearomatization. However, in the dearomatization process the aromatics in the stock treated which go into the catalyst phase deactivates the catalyst so that it is not sufficiently strong to accomplish much averaging or other catalytic modification, even though the materials present in the remaining hydrocarbon layer are those which could be reacted in averaging. When the rafnate is treated with the same catalyst under the identical conditions, the averaging reaction takes place and this is accounted for by the fact that the treated stock is substantiallyffree from aromatics and the catalyst is not deactivated to an extent to interfere with the averaging or other modifying reaction.

It will be apparent that the control of the process is an important aspect of the invention and that it is not possible to interrelate the variables mathematically. However, it is believed that one skilled in the art, in view of the disclosure in this application, will be able to adjust the conditions without difficulty so as to obtain the desired new results.

These processes are adapted either for batch operation or for continuous operation. In a batch operation the hydrocarbons and the fluorides are brought together in desired amounts in aclosed container or autoclave, or they are preferably subjected to agitation and maintained under the desired temperature, pressure and other conl l ditions for the required length of time. The mixture is settled and the two layers separated. The operation would be much the same either for dearomatization or averaging. The process is well adapted for a continuous operation, and in view of the desirability of continuous and semicontinuous processes, on a commercial scale, the adaptability of the invention to these processes is important. In such a continuous process the fluorides and the hydrocarbons to be treated are fed to a continuous type mixer, which may have one or more stages, and maintained under the desired conditions during the mixing. The now through the mixerv may be continuous or intermittent and may be at a rate so that the hydrocarbons are in contact with the catalyst for the desired length of time. After the hydrocarbons and the catalyst have been mixed under the selected conditions the agitation maybe discontinued, as for example, by discharging hydrocarbons and the catalyst from a mixer into a separator, where two layers will form. The upper layer, if it is from the dearomatizing process, may then be sent to the averaging reaction zone and the lower layer may be sent to the catalyst regenerating system if its ability to extract aromatics is spent. Otherwise, it may be used to dearomatize an additional amount of feed stock before being regenerated. The flow ofthe feed stock and catalyst, either fresh or spent, in the dearomatizing process may be countercurrent in order to utilize Vfully theV capacity of the catalyst for extracting aromatics.

From the settler for the averaging reaction, the upper hydrocarbon phase may be Vfractionated to obtain the wanted products and the remainder of higher and/or lower boiling materials may be recycled Ato the averaging reaction Zone. The spent catalyst from the averaging reaction zone may be regenerated or used to extract aromatics from the feed stock, as explained heretofore.

Preferably the separating operation, when yapplied to either a batch or continuous operation, is carried out under the pressure used in effecting the reaction. Alternatively, vii the pressure is reduced some ofthe lower layer may redissolve and most of the boron trifluoride and some of the other light components may be released.

After the catalyst has been used in either the averaging or dearomatizing process it may be regenerated by withdrawing apart or all of the used or reused catalyst at any stage of the operation and subjected to a relatively high temperature, for example 250-600 F. vThis may be by way of a pot still, or by means of flash distillation. At this temperature substantially all of the uorides are liberated as gases. These can be collected and condensed and/or compressed and returned to the mixing zone or stored or otherwise used. Two stage regeneration is desirable, the rst stage being a flash distillation operated at a fairly low temperature to remove a major portion of the iiuorides, following which the balance may be removed in' a stripper at a higher temperature.

Alternatively, instead of distilling the luorides, the lower layer or catalyst phase may be treated with a. material which exerts a solvent action on the uorides and which is immiscible with the hydra arbons in the lower layer, or which forms a chemical compound or complex with the iluorides and from which the iluorides may be released later, for example .by heating. Such a 12 material may be an oxyfiuoboric acid, such as H3BF202 0r H4BF302.

Another alternative is to distill olf a part or most of the iiuorides from the lower layer at a relatively lower temperature and remove the rest of the fluorides by extraction with such a material. Substantially all of the uorides can be recovered by any of these processes and reused in either the averaging or dearomatizing processes.

The hydrocarbons in the upper layer also can be treated with a material such as an oxyuoboric acid, to extract iiuorides therefrom if this is desired.

The reference to a hydrocarbon fraction is intended to refer to a pure hydrocarbon as well as a mixture of hydrocarbons.

It will be apparent that the invention is capable of many applications and variations and I intend all of them to be included as are within the following claims.

VI claim:

l. A process which comprises treating a hydrocarbon' mixture containing aromatic and nonaromatic hydrocarbons with a composition comprising liquid hydrogen uoride containing boron trifluoride dissolved therein, whereupon aromatic hydrocarbons form a complex with said fluoride composition as the principal action; separating said fluoride composition containing said aromatic-fluoride complex as a heavier layer, and the hydrocarbons from which aromatics have thus been removed as a lighter layer; and then subjecting said dearomatized hydrocarbons, without the removal of any fluorides remaining therein, to the action of a catalyst comprising liquid hydrogen fluoride containing boron trifluoride dissolved therein which acts to modify the chemical structure of the non-aromatic hydrocarbons.

2. A process which comprises treating a hydrocarbon mixture containing aromatic and nonaromatic hydrocarbons with a composition comprising liquid hydrogen fluoride containing boron trifluoride dissolved therein, whereupon aromatic hydrocarbons form a complex with said nuoride composition as the principal action and deactivate said fluoride composition as a catalyst; separating said fluoride composition containing said aromatic-fluoride complex as a heavier layer, and the hydrocarbons from which aromatics have thus been removed as a lighter layer; and then subjecting said dearomatized hydrocarbons, without the removal of any uorides remaining dissolved therein, to the action of a catalyst comprising liquid hydrogen fluoride containing boron trifluoride dissolved therein which acts to modify the chemical structure of the non-aromatic hydrocarbons.

3. A process of dearomatizing a hydrocarbon fraction and catalytically modifying the hydrocarbons in the dearomatized fraction, which comprises adrnixing an aromatic-containing hydrocarbon fraction with a spent catalyst comprising liquid hydrogen nuoride containing a minor proportion of boron triuoride that has been used in the catalytic modification of hydrocarbons, to form hydrocarbon and spent catalyst phases under a pressure to maintain the hydrogen fluoride liquid and conditions such that the primary action is the transfer of aromatics from the hydrocarbon fraction into the spent catalyst phase, separating the hydrocarbon fraction as one phase and the aromatic-containing spent catalyst as another phase, catalytically modifying the hydrocarbons in said dearomatized fraction by hydrocarbon fraction in accordance with the first steps of the process.

4. A process of dearomatizing a hydrocarbon fraction and catalytically modifying the hydrocarbons in the dearomatized fraction, which comprises admiXing an aromatic-containing hydrocarbon fraction with a spent catalyst comprising liquid hydrogen fluoride containing a minor proportion of boron trifluoride that has been used in the catalytic modification of hydrocarbons, to form hydrocarbon and spent catalyst phases under a pressure to maintain the hydrogen fluoride liquid and conditions such that the primary action is the transfer of aromatics from the hydrocarbon fraction into the spent catalyst phase, separating the hydrocarbon fraction as one phase and the aromatic-containing spent catalyst as another phase, regenerating the fluorides from the last mentioned phase; and in the presence of any fluorides that may be contained in said dearomatized fraction, catalytically modifying said hydrocarbon fraction by treating it with a liquid catalyst comprising liquid hydrogen fluoride in which is dissolved a f minor proportion cf boron trifluoride, at least some of said fluorides being said regenerated iiuorides, under a pressure to maintain the hydrogen fluoride liquid and conditions such that the primary action is the catalytic modification of the hydrocarbons in said fraction, separating the modified hydrocarbon fraction as one phase and the catalyst after it is spent in the above catalytic modifying process as another phase, and using the spent catalyst to dearomatize the aromatic-containing hydrocarbon fraction in accordance with the first steps of the process.

5'. A process of dearomatizing a heavier hydrocarbon fraction containing primarily hydrocarbons having at least six carbon atoms and ca'talytically modifying the hydrocarbons in the dearomatized fraction in the presence 0f a light hydrocarbon fraction, which comprises admixing an aromatic-containing heavier hydrocarbon fraction with liquid hydrogen fluoride containing a minor proportion of boron trifluoride to form hydrocarbon and fluoride phases under a pressure to maintain the hydrogen fluoride liquid and conditions such that the primary action is the transfer of aromatics from the hydrocarbon fraction into the iiuoride phase, separating the hydrocarbon fraction as one phase and the aromatic-containing fluorides as another phase, catalytically modifying said dearomatized heavier hydrocarbon fraction without the removal of any iiuorides remaining therein, by treating it in the presence of a light hydrocarbon fraction with a liquid catalyst comprising liquid hydrogen iiuoride in which is dissolved a minor proportion of boron trifluoride under a pressure to maintain the hydrogen fluoride liquid and conditions such that the primary action is the catalytic modification of the heavier hydrocarbons in said fraction to form hydrocarbons lighter than in said fraction, and separating the hydrocarbon 14 fraction as one `phase and the catalyst as another phase.

6. A process of dearomatizing a heavier hydrocarbon fraction boiling above gasoline and catalytically modifying the hydrocarbons in the dearomatized fraction in the presence of a butane which comprises admixing an aromatic-containing hydrocarbon fraction boiling above gasoline with a spent catalyst comprising liquid hydrogen fluoride containing a minor proportion of boron triiiuoride -that has been used in the catalytic modification of hydrocarbons, to form hydrocarbon and spent catalyst phases under a pressure to maintain the hydrogen fluoride liquid and conditions such that the primary action is the transfer of aromatics from the hydrocarbon fraction into the spent catalyst phase, separating the hydrocarbon fraction as one phase and the aromatic-containing spent catalyst as another phase, catalytically modifying said dearomatized heavier hydrocarbon fraction by treating it in the presence of a butane with a liquid catalyst comprising liquid hydrogen fluoride in which is dissolved a minor proportion of boron triiiuoride under a pressure to maintain the hydrogen iiuoride liquid and conditions such that the primary action is the catalytic modification of the heavier hydrocarbons in said fraction to form hydrocarbons lighter than in said fraction, separating the modified hydrocarbon fraction as one phase and the catalyst after it is spent in the above catalytic modifying process as another phase, and using the spent catalyst to dearomatize the aromatic-containing heavier hydrocarbon fraction in vaccordance With the first steps of the process.

7. A process of dearomatizing a heavier hydrocarbon fraction boiling above gasoline and catalytically modifying the hydrocarbonsl in the dearomatized fraction in the presence of a butane which comprises adrnixing an aromatic-containing hydrocarbon fraction boiling above gasoline with a spent catalyst comprising liquid hydrogen fluoride containing a minor proportion of boron trifluoride that has been used in the catalytic modification of hydrocarbons to form hydrocarbon and spent catalyst phases under a pressure to maintain the hydrogen fluoride liquid and conditions such that the primary action is the transfer of aromatics from the hydrocarbon fraction into the spent catalyst phase, separating Ithe hydrocarbon fraction as one phase and the aromatic-containing spent catalyst as another phase, regenerating the fluorides from the last mentioned phase; and in the presence of any fluorides that may be contained in said dearomatized heavier fraction, catalytically modifying said fraction by treating it in the presence of a butane with a liquid catalyst comprising liquid hydro-gen fluoride in Which is dissolved a minor proportion of boron trifluoride, at least some of said fluorides being said regenerated fluorides, under a pressure t0 maintain the hydrogen'fluoride liquid and conditions such that the primary action is the catalytic modification of the heavier hydrocarbons in said fraction to form hydrocarbons lighter than in said fraction, separating the modified hydrocarbon fraction as one phase and the catalyst after it is spent in the albove catalytic modifying process as another phase, and using the spent catalyst to dearomatize the aromatic-containing heavier hydrocarbon fraction in accordance with the first steps of the process.

8. A process which comprises treating al hydrocarbon mixture containing aromatic and nonaromatic hydrocarbons with a composition comprising liquid hydrogen iluoride containing boron triiiuoride dissolved therein, whereupon aromatic hydrocarbons form a complex with said fluoride composition as the principal action; separating said uoride composition containing said aromatic-iluoride complex as a heavier layer, and the hydrocarbons from which aromatics have thus been removed as a lighter layer; and then subjecting said dearomatized hydrocarbons, without ythe removal of any fluorides remaining therein,

to the action of a catalyst comprising liquid hydrogen uoride containing boron triiiuoride dissolved therein, and in the presence of a normally gaseous hydrocarbon Ito form hydrocarbons having a boiling point between the dearomatized hydrocarbons and the normally gaseous hydrocarbon.

9. A process of dearomatizing a heavier hydrocarbon fraction containing primarily hydrocarbons having at least siX carbon atoms and catalytically averaging the hydrocarbons in the dearomatized fraction with light hydrocarbons, which comprises admixing an aromatic-containing hydrocarbon fraction with liquid hydrogen fluoride containing a minor proportion of boron trifluoride t form hydrocarbon and iluoridephases under a pressure to maintain the hydrogen iluoride liquid and conditions such that the primary action is the transfer of aromatics from the hydrocarbon fraction into the uoride phase, separating the hydrocarbon fraction as one phase and the aromatic-containing uorides as another phase, catalytically averaging said heavier hydrooarbons in said dearomatized fraction, without the removal of any iluorides remaining therein, with light hydrocarbons by ltreatment with a liquid catalyst comprising liquid hydrogen fluoride in which is dissolved a minor proportion of boron trifluoride under a pressure to maintain the hydrogen fluoride liquid and conditions such that'the primary action is the formation of hydrocarbons between said heavier and light hydrocarbons, separating the hydrocarbon fraction as one phase and the catalyst as another phase.

l0. A process of dearomatizing a heavier hydrocarbon fraction containing primarily hydrocarbons having at least six carbon atoms, and catalytically averaging the hydrocarbons in the dearomatized fraction with light hydrocarbons, which comprises admixing an aromatic-containing hydrocarbon fraction with a spent catalyst comprising liquid hydrogen fluoride containing a minor proportion of boron trifluoride that has been used in the catalytic modification of hydrocarbons, to form hydrocarbon and spent catalyst phases under a pressure to maintain the hydrogen fluoride liquid and conditions such that the primary action is the transfer of aromatics from the hydrocarbon fraction into the spent catalyst phase, separating the hydrocarbon fraction as one phase and the aromatic-containing spent catalyst as another phase, catalytically averaging said heavier hydrocarbons in said dearomatized fraction with light hydrocarbons by treatment with a liquid catalyst comprising liquid hydrogen fluoride in which is dissolved a minor proportion of boron trifluoride under a pressure to maintain the hydrogen fluoride liquid and conditions such that the primary action is the formation of hydrocarbons between said heavier and light hydrocarbons, separating the hydrocarbon fraction as one phase and the catalyst after it is spent in the above catalytic averaging process as another phase, and using the spent catalyst 16 to dearomatize the aromatic-containing heavier hydrocarbon fraction in accordance with the rst steps of the process.

l1. A process of dearomatizing a heavier hydrocarbon fraction boiling above gasoline and catalytically averaging the hydrocarbons in the dearomatized fraction with a butane fraction, which comprises admixing an aromatic-containing hydrocarbon fraction boiling above gasoline with liquid hydrogen fluoride containing a minor proportion of boron trifluoride to form hydrocarbon and fluoride phases under a pressure to maintain the hydrogen fluoride liquid and conditions such that the primary action is the transfer of aromatics from the hydrocarbon fraction into the fluoride phase, separating the hydrocarbon fraction as one phase and the aromaticcontaining uorides as another phase, regenerating the iluorides from the last mentioned phase, catalytically averaging said heavier hydrocarbons in said dearomatized fraction, without the removal of any uorides remaining therein, with a butane fraction by treatment with a liquid catalyst comprising liquid hydrogen fluoride in which is dissolved a minor proportion of boron triiiuoride under a pressure to` maintain `the hydrogen fluoride liquid and conditions such that the primary action is the formation of the hydrocarbons between butane and said heavier hydrocarbons, separating the hydrocarbon fraction as one phase and the catalyst as another phase.

12. A process of dearomatizing a heavier hydrocarbon fraction boiling above gasoline and catalytically averaging the hydrocarbons in the dearomatized fraction with a butane fraction, which comprises admixing an aromatic-containing hydrocarbon fraction boiling above gasoline with liquid hydrogen uoride containing a minor propportion of boron trifluoride, to form hydrocarbon and fluoride phases under a pressure to maintain the hydrogen fluoride liquid and conditions such that the primary action is the transfer of aromatics from the hydrocarbon fraction into the fluoride phase, separating the hydrocarbon fraction as one phase and the aromatic-containing fluorides as another phase; catalytically averaging said heavier hydrocarbons in said dearomatized fraction, without the removal of any fluorides remaining therein, with a butane fraction by treatment with a liquid catalyst comprising liquid hydrogen fluoride in which is dissolved a minor proportion of boron triuoride under a pressure to maintain the hydrogen fluoride liquid and conditions such that the primary action is the formation of the hydrocarbons between butane and said heavier hydrocarbons, separating the hydrocarbon fraction as one phase and the catalyst as another phase.

13. A process of dearomatizing a' heavier hydrocarbon fraction boiling above gasoline and catalytically averaging the hydrocarbons in the dearomatized fraction with a butane fraction, which comprises admixing an aromatic-containing hydrocarbon fraction boiling above gasoline with a spent catalyst comprising liquid hydrogen iluoride containing a minor proportion of boron trifluoride that has been used in the subsequently mentioned catalytic averaging of hydrocarbons, to form hydrocarbon and spent catalyst phases under a pressure to maintain the hydrogen fluoride liquid and conditions such that the primary action is the transfer of aromatics from the hydrocarbon fraction into the spent catalyst phase, separating the hydrocarbon fraction as one phase and the aromatic-containing spent 17 catalyst as another phase; and in the presence of any fluorides that may be contained in said dearomatized fraction, catalytically averaging said heavier hydrocarbons in said dearomatized fraction with a butane fraction by treatment with a liquid catalyst comprising liquid hydrogen fluoride in which is dissolved a minor proportion of boron trifluoride under a pressure to maintain the hydrogen uoride liquid and conditions such that the primary action is the formation of the hydrocarbons boiling between butane and said heavier hydrocarbons, separating the hydrocarbon fraction as one phase and the catalyst after it is spent in the above catalytic averaging process as another phase, recycling the unreacted butane fraction to the averaging reaction, and using the spent catalyst to dearematize the aromatic-containing heavier hydrocarbon fraction in accordance with the rst steps of the process.

14. A process which comprises treating a hydrocarbon mixture containing aromatic and nonaromatic hydrocarbons with a composition comprising liquid hydrogen uoride containing boron trifluoride dissolved therein, whereupon aromatic hydrocarbons form a complex with said iluoride composition as the principal action; separating 18 said iiuoride composition containing said aromatic-fluoride complex as a heavier layer, and the hydrocarbons from which aromatics have thus been removed as a lighter layer; and then subjecting said dearomatized hydrocarbons, Without the removal of any fluorides remaining therein, to the action of a catalyst comprising liquid r hydrogen fluoride containing boron triuoride dissolved therein under conditions which catalytically crack the dearomatized hydrocarbons as a principal reaction.

15. A process of dearomatizing a hydrocarbon fraction, which comprises admixing an aromaticcontaining hydrocarbon fraction with a spent catalyst comprising liquid hydrogen uoride containing a minor proportion of boron trifluoride that has been used in lthe catalytic modication of hydrocarbons, to form hydrocarbon and spent catalyst phases under a pressure to maintain the hydrogen fluoride liquid and conditions such that the primary action is the transfer of aromatics from the hydrocarbon fraction into the spent catalyst phase, and separating the hydrocarbon fraction as one phase and the aromatic-containing spent catalyst as another phase.

ROBERT E. BURK. 

